Posted
by
samzenpus
on Monday February 18, 2013 @09:40AM
from the deadliest-bag dept.

theodp writes "A paper by Wharton's Jonathan Klick and Joshua Wright suggested that San Francisco's eco-friendly ban on plastic bags might actually be killing people. Klick and Wright found that food-borne illnesses in San Francisco increased 46% after the bag ban went into effect in 2007, with no such uptick in neighboring counties. Most likely, the authors concluded, this was due to the fact that people were putting their food into dirty reusable bags and not washing them afterward. But Tomas Aragon, an epidemiologist at UC Berkeley and health officer for the city of San Francisco, begs to differ, arguing that in order to establish a link between the bag ban and illnesses, the authors would have to show that the same people who are using reusable bags are also the ones getting sick. Aragon offers an alternative hypothesis for the recent rise in deaths related to intestinal infections, noting that a large portion of the cases in San Francisco involve C. difficile enterocolitis, a disease that's often coded as food-borne illness in hospitals which has become more common in lots of places since 2005, all around the U.S., Canada, and Europe (for yet-unexplained reasons). 'The increase in San Francisco,' he suggests, 'probably reflects this international increase.'"

If you go to the source paper [ssrn.com] you'll notice both authors are from law school. So, that being said, why are they writing about a medical issue and using questionable statistics?

Here is the abstract:

"Recently, many jurisdictions have implemented bans or imposed taxes upon plastic grocery bags on environmental grounds. San Francisco County was the first major US jurisdiction to enact such a regulation, implementing a ban in 2007. There is evidence, however, that reusable grocery bags, a common substitute for plastic bags, contain potentially harmful bacteria. We examine emergency room admissions related to these bacteria in the wake of the San Francisco ban. We find that ER visits spiked when the ban went into effect. Relative to other counties, ER admissions increase by at least one fourth, and deaths exhibit a similar increase. "

- legal abortion turned your daughter into a herpes-ridden slut- helping poor people treat their diabetes just leads to more fatties, yo- health insurance mandates are so bad that they drive people to drink- hey, you know what would really solve our health care problems? Tort reform.

Just use plastic. The carbon footprint is lower than paper evidently [uoregon.edu]. People think paper is better because it can decompose, but it doesn't in landfills buried under tons of other trash without air for the bacteria. And it doesn't really matter: litter is ugly but harmless compared to ocean acidification or climate change.

The paper bags are reusable at home though; plastic bags are really good for little else than trash bags, and the store bags have become so thin that they tear by the time I get my groceries put away. Paper bags, on the other hand, can be reused for countless things; I make them into books, cards, writing paper, etc. etc. Also you can throw paper bags into a home compost pile.

On what planet do people actually have time to hand-wash a dozen bags each week? Not on mine... So nobody I know ever washes these things. When they *look* dirty (which might be too late) people throw them away.

Even when you use a reusable bag, the sensible thing to do with certain kinds of food - especially uncooked meat - is to put them in a plastic bag. This plastic bag will protect the reusable bag, your car, and your fridge, from being contaminated.

In any case, this whole ban on plastic bags is nothing short of idiocy. Plastic bags *are* reusable, and people (e.g., me) do reuse them all the time, for anything from collecting garbage, carrying wet clothes from the pool, collecting dog excrement or cat litter, etc., etc. If people won't have these bags from the supermarket, they would buy them anyway. Heck, when was the last time you saw anyone throwing away plastic shopping bags, without reusing them first?

Those crappy $0.99 "reusable" bags that are not much more than the disposable bags they replaced aren't worth using.

We bought some heavy canvas bags. The handles are stitched down the sides of the bags to the bottoms. They don't break, they machine wash, and they hold a lot more content than those crappy bags hanging at the grocery store registers.

The bags we use came from the crafting store. They're sold as bags to be decorated with fabric paint. Ours are just plain, but we bought them there because they were a lot less expensive than buying similar bags elsewhere.

I generally am skeptical of anyone publishing claims that are outside their field of expertise. As the rebuttal [berkeley.edu] from Tomas J. Aragon, MD, DrPH, Health Officer, explained there are some serious defects in their study:

"The basic study flaw is that persons that use reusable bags frequently may not be the same persons that were diagnosed with
gastrointestinal bacterial infections in their study. This is the reason epidemiologists will not
use ecological studies to test causal hypotheses. At best, ecologic studies raise epidemiologic
causal hypotheses but cannot test them."

The change was 45 percent. Some of that is chance, like the global spread of disease mentioned in the summary. Without other data points, we have no way of knowing if the effect of banning plastic bags is 0 percent or 30 percent. I have no idea how big it has to be for somebody to have noticed. Do we know that public health officials are not scratching their heads, trying to understand the sudden rise in food-borne disease that spreads over the western world?

The paper doesn't say anything about the population dropping like flies.

It says that 5.4 additional people died. I would like to see the other 0.6 of the last person to die.

I am not sure if their conjectured mechanism is plausible. We have a ban where I live (San Jose, CA) and plastic bags are still allowed for produce, meat, etc. The law in SF is the similar. So the reusable bag doesn't actually touch the food. It only touches the packaging or wrapping.